Aura and buff are interchangeable terms... when you set maxauras, you're setting both. There is no mechanism in nUI5 to have one and not the other.
As for the cooldown bar, the slash commands are all documented here:
http://www.wowinterface.com/forums/s...ad.php?t=21199
- /nui hud cooldown
This option toggles display of in-HUD spell cooldown bar, cooldown alert messages and cooldown sounds on and off.
- /nui hud cdalert
When the in-HUD spell cooldown bar is enabled, this option turns the display of ready messages on and off.
- /nui hud cdsound
When the in-HUD spell cooldown bar is enabled, this option turns the playing of ready sounds on and off.
- /nui hud cdmin {n}
Sets the minimum amount of time required for a spell to be displayed on the cooldown bar when it first begins the cooldown. If the initial cooldown period is less than {n}, it won't display. The default value is '/nui hud cdmin 2'